Environmentally friendly waste water treatment

Powerstax and their high-energy partners DP Energy have provided a power solution for an electrochemical water-treatment system (electro-coagulation) used for removal of dissolved and suspended contaminants from waste-water streams. The development system has successfully completed a commercial-scale pilot trial at the British wastewater treatment works of a multinational manufacturer.

The system has been developed to treat effluent from the manufacturer’s paintwork department, specifically reducing phosphate concentration in the waste water. Electro-coagulation technology is used to remove phosphates and reduce landfill more effectively than traditional chemical treatment.  By removing the requirement for chemical dosing, and producing a smaller quantity of sludge for disposal, the technology offers major environmental and economic benefits.

Minimising the energy consumption required by the system was a major design criteria and Powerstax developed a highly efficient bespoke power solution for the application. The custom designed 20VDC/ 500A 19” rack mounted HF Power Source provided the end user with the key feature of reversible current flow. The power supply offers external control of output voltage and current and output monitoring using 0-10V isolated analogue signals.

Requiring a three phase, three wire supply (Public Low Voltage Network) input voltage of 400VAC, the power supply has a power factor typically >0.94 at full load and efficiency >88% (after Power Factor). Full protection features as standard include output current protection with internal electronic control of current limit and short circuit protection. Front panel LED’s indicate power on, unit on, over-temperature, low current alarm, under Voltage and over voltage. External control is provided for enable/run (stop/start), reverse output and alarm (trip) reset. A full range of alarm signals are available to provide information to central control systems including low current, on/standby, mains on and enable, over voltage, over current, high temperature, polarity normal, polarity reverse. The rack mountable unit has dimensions of 482.6mm x 394.1mm x 212.7mm and an ambient operating temperature range of 0 to +40ºC.

Outstanding results were achieved at the waste water treatment plant with up to 95% phosphate removal and up to 70% landfill reduction due to lower sludge volumes.  Other benefits of the technology include reliability of materials supply and improved control of the process.

Tim Worley, CEO Powerstax plc comments; “This project is an excellent showcase for the high efficiency, rugged power conversion systems which we excel at. Working closely with both DP Energy and the end user we have provided a bespoke power conversion system which has now proved itself in the field.”